15HP Mercury 1989 2 stroke long shaft

I tried starting my 15HP Mercury for the first time a almost 2 years. I pulled the choke once and then a second time. I pulled the cord and the motor started but only putt putted about 30 seconds and stopped. I turned the choke button toward the right to the Fast where it also says Start and pulled the cord again. It putt putted a couple seconds and now does not start. Not sure if I flooded the motor. I bought new spark plugs and going to try again next weekend when I have time. Can anyone provide this novice how to start the 15HP. I was told the outboard is an 1989 with a tiller handle. Should I pull the choke button out and turn the know all the way to the right then pull the cord. I need to fill the bucket full of water to submerge the lower unit which takes time and energy. Any suggestions would be helpful.

Yes pull the knob out and turn to the right then start.

Perhaps I misread again.----Did you run the motor for 30 seconds without water to the impeller ?------Now deciding to put it in a bucket to run it some more ?

Sounds like it's a bigger job for our OP to fill water container again. Just make sure it is at least 4" above the level of the water pump. Maybe it was stored with gasoline still in the carb/fuel pump. Might need a carefull cleaning. Question: Will it stay running if you keep squeezing the primer bulb?

I ran the motor with the lower unit fully immersed in a bucket of water. I now bought new spark plugs and plan to try again this weekend. I'm thinking of spraying a little mixed gas oil in the carb to see if it kicks on.

Thank you Timguy, I did have the lower unit fully immersed in bucket of water. I hook up the 15 HP with tiller to the fuel line from my boat so I cannot pump the bulb when pulling the cord. I'll have to ask a friend help pump while I try to start it. I bought new spark plugs and plan to spray a little mixed oil gas in carb to see if will kick over. Do you think that will work.?

Yes that should work. Make sure the water is about 6" above where the lower unit bolts to the center leg/housing.

Pull the knob out 2 times turn to the right and try to start.